and this is neither an advertisement nor an endorsement.) It sounded interesting to me.

Gympact

There are plenty of ways to motivate you to work out, but the app Gympact does something quite clever and unique. They hit you where it hurts…right in the wallet. The concept behind Gympact is that you set a monetary consequence for when you miss your work outs, typically a $1 or so. Then anytime you miss a work out you committed yourself to, you pay the fine. But it doesn’t stop there. What if you’re a good boy or girl and hit all of your workouts that week? Well friend, you get a share of all the slacker’s fines that week.